Lapping machine



Jan. 28, 1930. w. F. GROENE 1,744,886

LAPPING MACHINE Filed Feb. 7,1928 s Sheets-Sheet 1 INVEN TOR. WM 4 ATTORNEY5 Jan. 28, 1930; I GROENE 1,744,886

LAffING MACHINE led Feb. 1928 8 Sheets-Sheet 2 I NVENTOR (MM 714 n] MATTORNEY Jan. 28, 1930; w F; GROENE I 1,744,886

LAPPING MACHINE Filed Feb. 1928 8 Sheets-Sheet 4 INVIIENTO WA. 4 m

ATTORNEY)" 8 Sheets-Sheet 6 ATTORNEYS Jan. 28, 1930. w. F. GROENE1,744,886

LAPPING MACHINE Filed Feb. "I, 1928 8 Sheets-Sheet 7 ATTORNEYS Patented7 Jan. 28, 1930 UNITED STATES v PATENT OFFICE Y WILLIAM F. GROENE, OFCINCINNATI, OHIO, ASSIGNOR TO THE R. K. LE BLOND MACHINE TOOL COMPANY,OF CINCINNATI, OHIO, A CORPORATION OF DELAWARE mirrme Application filedFebruary My invention relates tolapping machines in which the bearingsand the crank pins are lapped and polished to a true bearing surface insuch a way as to approach very nearly actual working conditions of theshaft.

Prior practice necessitated separate operations for lappingthe mainbearings and the crank pins, while my machine laps the bearings' and thepins in one operation, thus producing concentric Working surfaces withrelation to the true centers of the crank shaft Other advantages, novelstructures and improvements over other mechanisms for like purposes willbe pointed out as the description proceeds, in which I will set forth inde-- tail onepreferred embodiment of myinvention and the noveltyinherent, wherein I will state in the appended claims.

In the drawings I Figure 1 is a front elevation of the lappingmechanism. 7

- Figure 2 is a top plan view of the machine.

Figure 3 is a perspective of the rear of the machine.

Figure 4 is a vertical section through the machine showing the leverscollapsed with the lapping arms in lapping position.

- Figure 5 is a vertical section through the machine showing the leversand the lapping arms expanded.

Figure 6 is a complete lapping unit detached from the machine.-

Figure 7 is an elevation of the headstock and driving mechanism of themachine.

Figures 8 and 9 are a top plan and front elevation of the spindle timingratchet.

Figure 10 is a section through the head stock showing the componentparts of the spindle and. driving mechanism.

Figure 11 is a section through the eccentric taken on the lines l111 ofFigure 7.

Figure 12 is a diagrammatic perspective of I. the air supply tothe-cylinders.

Figure 13 is an alternate formof the lapping unit.

Figure 14 is a diagram of the electric time control.

MACHINE 7, 192a." Serial No. 252,588.

the main bed of the machine, while the lapping arms are confined infixed vertical planes. This lateral motion is derived from an adjustableeccentric mounted within the head stock.

The revolving crank shafts impart reciprocating motion to the lappingarms which are guided and held from lateral movement. Each arm can befitted with grinding stones or a solid block, whichever is preferred.

Lubrication to the lapping surfaces is provided through a series oftubes coming from a common source such as a circulating pump. Thepressure for lapping is obtained by means of springs compressed adetermined amount to limit the depth of lap for a given number ofrevolutions of the crank shaft. The springs limit the depth of lapautomatically because the pressure exerted by them is.

gradually decreased to zero while the springs are returning to normalunfiexed condition.-

on a pivoted member which carries the lapping arms, their guides andlubricating hose.

away from the crank shaft when air is passed into a cylinder locatedwithin the lines of the bed of the machine.

The above mentioned member does not come into play before an outermember has been thrown back by means of another cylinder which actuatesa toggle between the two members and causes them to separate. The innermember does not move until the limit of the toggle has been reached.Simultaneously, While the. limit of the toggle is reached, the lappingarms are locked from sliding by a chain pulling on a latch mountedwithin the bearings of the lapping arms. Mounted on the outer memberthere is a cam which operates two whistle valves .through which the airis excluded from the vertical cylinder and by-passed into the secondhorizontal cylinder below the bed of the machine. This by-passing of theair to the horizontal cylinder causes the pistons to swing the inner andouter members away from the machine as a single unit and consequentlydraw the lapping arms away from the crank shaft in such a manner thatthey will be in their proper position to come forward and receive thenext crank shaft when it has been put in the machine.

The return to osition of lapping is a reverse sequence 0 operation asdescribed for the removal of the work.

My machine stops after a predetermined number of revolutions of thecrank shaft necessary to produce the proper bearing surface. This isaccomplished by means of a suitable electrical time element showndiagrammatically in Figure 14. My machine can also be stopped at will bysuitable mechanism described later. While the machine can be stoppedduring any part of a revolution, it is' essential that the crank shaftsbe removed and installed while in a definite position so as to provide aconstant relation of the shafts to the lapping arms. I have accomplishedthis by means of a ratchet and slidably mounted stopping post. Thisstopping post cannot be operated before the power to the spindle drivingthe crank shaft has been disconnected. The power is applied through anysuitable clutch arrangement combined with a spindle and face platesimilar in construction to lathes.

I have shown the main stand or bed 1 upon which is mounted a slidingplate 2 confined to a definite reci rocating motion by the eccentric 3rotata ly mounted in the head stock 4 and sliding block 5. Since thehead stock and tail stock 5 are fixedly mounted on the base plate 2 theymove back and forth with the base plate as a single unit, and therebytransmit horizontal reciprocating lateral motion to the crank shaftG'when it is placed between the centers of the head and tail stocks.

The eccentric 3 consists of a shaft 7 having keyed thereon the gear 8which meshes and is driven by the gear 9 keyed on the main spindle 10.The shaft 7 is journaled in the head' stock at 7 7 and has an eccentricportion 11 on its left end which protrudes beyond the outside of headstock. Upon this eccentric end 11 I mount a bushing 12 with an eccentricdrilled hole 12 therein. After assembling these parts I rotate thebushing 12 on the eccentric end of the shaft so as to fix the movementof the sliding plate 2 to the desired amount. I then clamp the bushingfast to the eccentric of the shaftby means of the locknut 14. Therotation of the two eccentrics as a single unit within the sliding blockcauses the sliding plate to move back and forth because the-slidingblock is confined in the bifurcated member 15 which is fixed on the mainstand of my machine. Since the sliding block 5- is confined to movementin the vertical plane and the sliding plate 2 in the horizontal plane,it is apparent that the resultant motion of the sliding plate is ahorizontal reciprocating motion due to the eccentric circle described bythe surface of the bushing 12 with relation to the center of the hole inthe sliding block. Varying the rethe slight variations encountered inthe lengths of the crank shaft-s.

Disengagement of the clutch is accomplished by clockwise motion of thelever 20 pinned to the shaft 21. The shaft 21 has mounted thereon a fork22 which engages the slidably mounted collar 23 on the spindle 10. Thiscollar has a through pin 24: free to slide in a slot 25 in the spindleand connects the collar 23 with the clutch release rod 26 whichdisengages the clutch through the adjustable bell crank 27. The faceplate 28 of the spindle contains a stud 29 which engages and drives thecrank shaft to be lapped, as will be described below.

In order to index the crank shaft with relation to the lapping arms Ihave rigidly mounted on the spindle a ratchet wheel 30 having a shroudedportion 30 with a stopping point slot 31 which is engaged by the slidinglatch 32 mounted in the head stock 4. This latch is confined tohorizontal movement and is moved by the lever 33 on the shaft 33 whichhas a pinion 34 fastened thereon and engages the rack teeth cut on thelatch.

As a matter of precaution I provide an intcrlock pin 36 held slidably ina housing 36 grammatically in Figure 14.. lVhcn the lever 20 on thelathe is thrown to engage the clutch a small limit switch 37, which hascontacts normally held open by a spring, will also be depressed, closingthe contacts, which will energize a relay 3?". After a definite time haselapsed, as determined by the setting of the relay, a contact will beclosed in the relay between the terminals 25, t, causing the contactor37 to pick up and in turn energize the solenoid, which will trip out theclutch and throwthe lever 20 back will= then be free to revolve;

to the stop position, which will release the limit switch and cause itto open its contacts.

This in turn will de-energize the relay, which.

will reset and de-energize the contactor and solenoid, leaving theequipment ready for a new start.

The shaft 33 and the shaft 21 have cams 40 and 41 thereon. Power to themachine is cutoff by rotating the shaft 21 with the lever 20 in aclockwise direction. When the shaft 21 is rotated in this direction itrotates the surface 41 of cam 41 away from the bottom endof theinterlock bar 36 which falls down to the position shown and allowsitslupper end to slide on the surface of the cam 40. The lever 33 cannow be rotated in a clockwise direction and pull the latch 32 to theleft where it will engage the slot 31 and index the spindle for removingthe crank shaft that has been lapped. The interlock bar 36 isslidablymounted in the housing 36 rigidly mounted on the head stock. Byreferring to Fig. 7 it can be seen that lever 20 cannot be rocked to theleft until the notch 32 in the latch 32 has been moved to the right, andbridge the shroud of the ratchet wheel which The lever 33 must rotatethe cam 40 away from the upper end of the interlock bar 36, because thelower end of the interlock bar 36 can not ride up over the surface ofthe cam 41 while its upper end is against the surface of the cam 40,which prevents the interlock bar 36 from sliding upward The machine isat rest and the spindle is indexed for the next crank shaft to be lappedwhen the parts are in the positions shown in full lines in Fig. 7.

If the slot 31 on the ratchet wheel, which is part of the spindle,passes the latch 32 it can be brought to the point of engagement byrotating the ratchet wheel with an up and down movement of the pawlhandle 42 mounted on a projecting surface 43 of the ratchet wheel andheld in place by the plate 44 which is screwed to the face plate of thespindle. This plate does not interfere with the free movement of thepawl handle. The pawl 45 mounted on the pawl handle does not engage theratchet wheel until it is lifted off the trip 45 mounted on the slidingplate 2. This trip prevents the pawl from riding the ratchet wheel whilerotating during the lapping operation. The pawl 45 engages the ratchetwheel when the compression on the spring 46 is released by raising thepawl handle so that the pawl tip 45 does not'bear on the trip 45 Sinceeach fly wheel flange of crank shafts have holes therein, I utilizethese holes to drive the crank shaft by placing stud 29 in one of themWhile placing the crank shafts between centers. The, holes are jigdrilled thereby enabling me to properly and definitely locate the crankshaft quickly because the stud 29 and the slot 31 are fixed on thespindle with, relation to each other. By placin the stud in the samehole 'on each crank s aft,

I automatically locate the crank pins and bearings with relation to thelapping arms and do not have to delay the lapping'operation by locatingeach lapping unit sepa'rately. This is also advantageous because I putin and remove the crank shafts when the lapping arms are expanded andaway from the machine. I I

Figures 6 and 13 show two types of lapping arms which may be used on mymachine. The

difference between the two is in the spring control element.

The lapping arms 47 and 48 are arranged in pairs, using as many pairs asdesired. In the one type a spring 46 is fastened in the lapping arm 47and passes through a boss 48 on the lapping arm 48 and connects to athreaded stud 49 having on it a wing nut 50 which bears on the boss 48.By screwing down or up on the wing nut 50 I increase or decrease thetension of the spring and hence the lapping pressure. The lapping armshave concave surfaces 47 and 48 upon which I fasten lapping stones 52 ofsufficient thickness to elevate them above the concave surfaces therebyproviding ample clearance for the lubricant to carry away all chips orforeign matter which would mar the surface being lapped. The lubricantis suppliedfrom a pump 53 at the rear of the machine and driven by meansof a belt '54. The'lubricant passes from the pump through the flexiblehose 55 to the manifold pipe 56 mounted 011 the movable frames (to bedescribed) int-o individual flexible hoses 57 and finally through the Ied in the tubular rods 61 and pinned therein by the pin 61*. Thesetubular rods are then pinned to the sliding blocks 62 by the pin 62. Thesliding blocks 62 are the means provided to confine the lapping arms inthe vertical planes and do so because they in turn are slidably mountedand guided in the bifurcated members 63 which are adjustably mount ed onthe shaft 63% This shaft is fixedly mounted on the extended arms 84 ofthe frame member 84.

The right hand ends of the tubular rods are the supports for the lappingarms and are slidably mountedin the pivoted bearings 59 and 60. Thesebearings are of the hinge type and have a common support in theshaft 58which is fixed in the frame 84.

The frame 84 is employed to retract and advance the lapping arms andanother frame 68 is used to open the arms. The two frames outer frame 68to swing back on the shaft 71 which also serves as a pivotal mountingfor the vertical cylinder 64. \Vhile the frame 68 is moving away fromthe machineit pulls on the chains or cables 7 2 through the links 73which are fixedly mounted on the shaft- 74 in the frame 68. Latches 76are pivoted in the pivoted slide bearings 59 and 60, on pins 77 and heldout of engagement with the tubular rods 61 by the springs 77 The chainspull on the levers 75 of the latches 76 rotating them to right and leftrespectively. The rotation of the latches about their pins causes thelower surfaces of the latches to clamp down on the tubular rods (31preventing them from sliding and holding them in place while they aremoved away from the work. These latches are operated and set by a veryslight movement of the frame 68 and during the time-the frame is movingthe rest of the way the chains pulling on the levers 75 of the latchescause the lapping arms to separate by the rotation of their supportingbearings 59 and about the shaft 58.

During the time that the latching and spreading of the arms is takingplace, I bypass the air to a horizontal cylinder 81 by means of the cam78 which is rigidly mounted on the frame member 68. Before the frame 68has completed its outward movement the lower surface of cam 78 engages awhistle valve 80 located in the air line, so as to admit air through apipe 80 which is connected to the said horizontal cylinder 81. Thiscylinder is rigidly mounted on the under side of the main bed of themachne. The valve is so arranged that the by-passing of the air into thecylinder 81 does not exclude the air from the cylinder 64 because it isnecessary to maintain pressure within the cylinder 64. \Vithin thecylinder 81 is'a piston 81 whose )lStOIl rod 82 is'connected to theframe 84' y means of a link 83 having pivot pins 85.

and 86, one to the frame 84.

The frame 84 is normally held in locked position by means of the gravityactuated latch 87, which is mounted pivotally by means piston rod andone to the .of a pin 88 to theframe 1, and has a notched -end 89 whichengages the lug plate 90 fast on the frame 84. As can be seen, I haveslotted the hole 91 in the link 83 which receives the pin 86 ontheframe. This slot is provided to allow for the movement required to'release the latch 87.1 The link 83 has its inner end formed to engagethe end 87 a of the latch and thus release it from position of latching'way control valve 81 I admit air through the pipe 92* into the righthand end of the hori .zontal cylinder 81 (Figures 4 and 5) whose pistonpulls the frame 84 towards the machine until the latch 87 drops over thelatch bar 90 and locks the frame 84 in place. This action also pulls theframe 68 inwardly because of the toggle. When the frames are in thisposition the upper whistle valve 92 will have been operated by the uppersurface of the cam 78 and is so connected as to by-pass air through thepipe 92* into the top of the vertical cylinder 64. This results inpulling down the rod causing the toggle joint 67 to collapse and pullthe frame 68 into place. \Vhile the frame 68 is moving into place thelapping arms are closed over the surface to be lapped by the springs 46,and as the frame 68 comes to rest it releases the pull on the chainwhich in turn releases the latch 76 and leaves the machine in conditionto apply power and begin lapping. Having thus described my invention,what I claim as new and desire to secure by Letters Patent, is

1. In a lapping machine, the combination of means for rotating a crankshaft, lapping V and move with the surfaces of the crank shaft,

to be lapped, under power applied thereto by said shaft, and poweroperated means for apl 'n and removin the lappin members frfi m the saidsurfac les to be lapffed after a predetermined number of rotations ofthe crank shaft, said rotating means comprising members for giving apredetermined position of the crank shaft with relation to said lappingmembers.

3. In a lapping machine, the combination of means for rotating a crankshaft, lapping members arranged in pairs to engage over and move withthe surfaces of the crank shaft to be lapped, under power appliedthereto by said shaft, and power operated means for applying andremoving the lapping members from the said surfaces tobe lapped after apredetermined number of rotations of the crank shaft, said rotatingmeans comprising members for giving a predetermined position of thecrank shaft withrelation to said lapping members, and means forinhibiting actuation of said rotating means until said predeterminedposition is attained.

4. In a lapping machine, the combination of means for rotating a crankshaft, lapping members arranged in pairs to engage over and move withthe surfaces of the crank shaft to be lapped, under power appliedthereto by said shaft, and power operated means for ap- "plyingand-removing the lapping members from the said surfaces to be lappedafter a predetermined number of rotations of the crank shaft, saidrotating means comprising members for giving a predetermined position ofthe crank shaftwvitli relation to said lapping members, and means forpreventing application of the lapping members until said predeterminedposition has been attained.

5. Ina lapping machine, the combination of means for rotating a crankshaft, lapping members arranged in pairs to engage over and move withthe surfaces of the crank shaft to be lapped, under power appliedthereto by said shaft, and power operated means for applying andremoving the lapping members from the said surfaces to be lapped after apredetermined number of rotations of the crank shaft, said rotatingmeans comprising members for giving a predetermined position of thecrank shaft with relation to said lapping members, and means forinhibiting actuation thereof until said predetermined position isapplied, and means for preventing application of the lapping membersuntil said predetermined position has been attained.

6. In a lapping machine, the combination of means for rotating acrankshaft, lapping members arranged in pairs to engage over and move withthe surfaces of the crank shaft to be lapped, under power appliedthereto by said shaft, and power operated means for applying andremoving the lap I ping members from the said surfaces to be lappedafter a predetermined number of rotations of the crank shaft, saidrotating means comprising members for giving a predetermined position ofthe crank shaft with relation to the lapping members at the start andfinish of every lapping operation.

7. In a lapping machine, the combination of means for rotating a crankshaft, lapping members arranged in pairs to engage over and move withthe surfaces of the crank shaft to be lapped, under power appliedthereto by said shaft, and power operated means for applying-andremoving the lapping members from the said surfaces to be lappedafter apredetermined number of rotations of the crank shaft, said meanscomprising a movable frame on which said lapping members are mounted,and a member movable fwith relation to said frame and connected to the".

lapping members'so as to open the same thereby releasing them from thecrank shaft lapped, and means for applying and removing the lappingmembers from the said surfaces to be lapped, said means comprising amovable frame on which said lapping members are mounted, and a membermovable with relation to said frame and connected to the lapping membersso as to open the same thereby releasing them from the crank shaftsurfaces, said lapping members having means to lock them in their openposition.

9. In a lapping machine, the combination of means for rotating a crankshaft, lapping members arranged to engage over and move with thesurfaces of the crank shaft to be lapped, and means for applying andremoving the lapping members from the said surfaces to be lapped, saidmeans comprising a movable frame on which said lapping members aremounted, and a member movable with relation to said frame and connectedto the lapping members so as to open the same thereby releasing. themfrom the crank shaft surfaces, and power means for actuating said frameand saidvr novable member in a predetermined sequence.

10. In a lapping machine, the combination of means for rotating a crankshaft, lapping members arranged to engage over and move with thesurfacesof the crank shaft to be, lapped, and means for applying and removfaces,and power means for actuating said frame and said movable member in apredetermined sequence, said sequence being as follows ':a movement ofthe'movable member to open and lock the lapping members, a movement ofboth the movable frame and movable member to withdraw the lappingmembers, a movement of both the'frame and the movable member to advancethe lapping members, and a movement of the movable members to unlock andpermit the closure of the lapping members over the surfaces to belapped.

11. In a lapping machine, the combination of means for rotating a crankshaft, lapping members arranged to engage over and move with thesurfaces of the crank shaft to be lapped, and means for applying andremoving the lapping members from said surfaces to be lapped, said meanscomprising a movable frame on which said lapping members are mounted,and a member movable with relation to said frame and connected to thelapping members so as to open the same thereby releasing them from thecrank shaft, and

means for inhibiting the movement of the movable frames during thelapping operation.

12'. In a lapping machine. the combination of means for rotating a crankshaft, lapping members arranged to engage over and move with thesurfaces of the crank shaft to be lapped, and means for applying andremoving the lapping members from said surfaces to be lapped, said meanscomprising a movable frame on which said lapping members are mounted,and a member movable with relation to said frame and connected to thelapping members so as to open the same thereby releasing them from thecrank shaft, and means for inhibiting the movement of the movable framesduring the lapping operation, and a means provided on the power actuatedmeans to release said inhibiting means after said movable frame foropening the lapping means has moved sufficiently to open and lock thelapping means in place.

13. In a lapping machine, a lapping member comprising upper and lowerlapping arms slidably mounted in a means for pivotally supportingsaidlapping means, and means for locking said lapping arms in apredetermined position when out of lapping position.

14. In a lapping machine, a lapping member comprising upper and lowerlapping arms slidably mounted in a means for pivotally supporting saidlapping means, means for locking said lapping'arms in a predeterminedposition when out of lapping position, and 1 means for releasing thelocking means when the arms are advanced to lapping position.

WILLIAM F. GROENE.

